(a) Field of the Invention
The invention relates to a 6 degree of freedom hand controller. More specifically, the invention relates to such a controller having a substantially spherical handgrip member with a substantially central point therein, the handgrip member being rotatable about said point to input rotational motion, while, to input translational motion, the effective lines of thrust pass through the point.
(b) Description of Prior Art
Hand controllers for spacecraft flight and/or manipulator control are known in the art. Thus, U.S. Pat. No. 3,296,882, Durand, Jan. 10, 1967, teaches such a hand controller having a somewhat spherical grip member 26. However, the grip member of the Durand patent is not mounted for rotational movement relative to its support shaft 25.
U.S. Pat. No. 3,260,826, Johnson, July 12, 1966, teaches a 6 degree of freedom hand controller. However, the handgrip member of the Johnson patent constitutes a cylindrical member rather than a spherical member.
U.S. Pat. No. 3,350,956, Monge, Nov. 7, 1967, also teaches a 6 degree of freedom hand controller. However, once again, the handgrip member 2 is not mounted for rotation relative to its support shaft 3. In addition, the system taught by Monge is complicated and requires a good deal of space.
U.S. Pat. No. 4,216,467, Colston, Aug. 5, 1980, also teaches a 6 degree of freedom hand controller. However, once again, the handgrip member 10 is not spherical in shape but is rather somewhat cylindrical in shape. In addition, Colston uses push buttons and levers to achieve the 6 degree of freedom.
U.S. Pat. No. 4,012,014, Marshall, Mar. 15, 1977, teaches an aircraft flight controller which uses a handgrip member which, once again, is not spherical in shape.
The hand controllers above-discussed, and others available in the art, are not particularly useful for a fully suited astronaut. Typically, a spacesuit operates with a pressure differential between inside and outside of 31/2 psi. The pressure itself, the construction of the suit and more specifically, the gloves required to resist this pressure cause a loss in dexterity to the astronaut. This condition is further aggravated by the addition of radiation shielding required for protection. To grip a conventional handle of the type illustrated in the above U.S. patents for any length of time becomes extremely to tiring due to the natural characteristic of the gloves return to their neutral position. Therefore, it is necessary to design a handle which requires minimum movement from the neutral position yet which can still be positively gripped by a fully suited astronaut.